To give you a sense of how big that team is, that's 40 times the number of employees at FedEx:

Mike from UPS can think through all those teams and all those workers, but there's still something that's a mystery for him: the sleigh. Not only does it have to move fast enough to deliver 9,000 presents a second, but estimating conservatively that each present weighs about a pound, Mike says it would have to haul 760 million pounds of cargo. Which would take nearly three hundred 747 planes to haul. Or perhaps just nine reindeer.

This is what the whole workforce looks like:

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Transcript

ROBERT SIEGEL, HOST:

It's Christmastime and kids everywhere are writing letters to Santa Claus. One particular letter got us thinking. It's from Lucy Drummond(ph), daughter of the senior national editor here at NPR News, Steve Drummond.

LUCY DRUMMOND: (Reading) Dear Santa, I hope you and Mrs. Claus are well. I think you are so kind but I have one question: How do you do it? Oh, by the way, you have a good sense of sight. Love, Lucy.

SIEGEL: How, indeed. How does Santa deliver presents to hundreds of thousands of children in a single night?

Well, as a public service to children everywhere, whoever wondered about this same question, Chana Joffe-Walt of NPR's Planet Money tried to find an answer.

CHANA JOFFE-WALT, BYLINE: Santa doesn't do interviews but there are two men who consider themselves sort of colleagues of Santa's, two men who believe they have a good sense of how exactly he does it. Here's the first, Paul Tronsor from FedEx.

PAUL TRONSOR: It's really about international business because, after all, that's what Santa really is doing here is a massive international operations, just like FedEx.

JOFFE-WALT: I spent a while talking to Paul from FedEx and a guy named Mike Mangeot from UPS about Santa. And the first thing we have to do is lay out some numbers. So, according to Pew Research Center, there are 760 million Christian children in the world. For the sake of simplicity, let's say each child gets one present. We know there's only one Santa to deliver those presents. We know he travels on a sleigh of undetermined size. And he has about 24 hours to get all the presents to all the kids.

Here's Mike with UPS.

MIKE MANGEOT: If you have to deliver to 760 million customers in a night, we kind of put that through a UPS prism to see what that would mean.

JOFFE-WALT: Mike says what you'd need to start is an international distribution center, like UPS has.

MANGEOT: That facility is 5.2 million square feet. It has 155 miles of conveyor belts and it employs about 9,000 people.

JOFFE-WALT: UPS has one of these. Santa, he says, would need 46 located all over the world, so he could fly by and replenish his supply throughout the night. Each one of those employs 9,000 people, so that's about 400,000 employees worldwide just to load presents on to Santa's sleigh.

TRONSOR: So, let's presume he wants to deliver packages in Florida, for example. He would not fly from the North Pole to Florida, 'cause there's a hundred million kids in between. He would develop an optimize to get him from the North Pole and make the most efficient stop, stop, stop, stop, stop all the way across the globe.

JOFFE-WALT: When Paul says he, he's not talking about Santa. He means 60,000 staff people. Another 100 people would file Santa's flight plan with the FAA ahead of time. Once Santa is in the air, you've got about 7,000 people tweaking his route in real time. Add to that a hundred meteorologists to make sure Santa doesn't, you know, fly into a blizzard.

UPS and FedEx ran these numbers, by the way, they're not just making them up.

So were close to half a million people so far. Double that, Mike the UPS guy says, because for this whole thing to work you'd need a ton of support staff.

MANGEOT: You can't just fly into a country. You have to get permissions to do that.

JOFFE-WALT: You need 100 people to secure fly-over rights and landing rights in every country Santa flies into.

And you can't just bring anything you want into each country, you have to clear customs. Paul, with FedEx, says Santa would need a staff of people who know everything about every country's rules, to make sure Santa will clear customs ahead of time.

JOFFE-WALT: You need drivers and pilots to get the presents from the North Pole to the distribution centers. It goes on and on. And for a grand total of how many people it would take to pull this operation off, Paul looks at how many people FedEx needs for one very busy day, compares it to Santa's 760 million customers, and he thinks...

TRONSOR: Santa is the head of this huge organization, so we expect that Santa would need about 12 million people.

JOFFE-WALT: So, Santa Inc. is 12 million employees.

TRONSOR: Santa Inc. is 12 million. It is massive. I don't know of any company that has the number of employees that Santa does.

JOFFE-WALT: These two guys, with FedEx and UPS, can look at their own businesses and figure out a lot about Santa's operation. But Santa does have certain trade secrets that are his alone. For Mike, with UPS, the biggest question he has about Santa's operations is that sleigh. Not only does it have to move fast, delivering almost 9,000 presents per second, but it's also carrying a huge amount of weight.

MANGEOT: Santa's sled has to be absolutely ginormous. If you assume conservatively that each of these 760 million children get a present that weighs one pound, that's 760 million pounds, which would take 295 747 aircraft to haul. Interestingly, that's about 50 more 747s than exists in the entire world. So that's - these reindeer are doing something really impressive on Christmas Night.

JOFFE-WALT: In the end, Mike and Paul both say they believe with 12 million people, about $10 billion and lots of technology, Santa's task does seem feasible. The remaining questions they have they just chalk up to Santa's main competitive advantage: Magic.